Corneal transplants, by which healthy corneal tissue of a donor is transplanted to replace diseased corneal tissue of a receiving patient, have become a common surgical procedure in the field of ophthalmology in recent years. In such a procedure, the donor tissue must be precisely cut to match the size and shape of the corneal tissue that has been removed from the patient who is to receive the transplant. In the past, the cutting of the donor tissue has commonly been done with the use of hand-held trephines. Hand cutting of the donor tissue, though, fails to provide enough precision for reliably accurate transplantation.
Mechanically aided corneal press devices have also been used, such as that described in U.S. Pat. No. 5,092,874 to Rogers, and U.S. Pat. No. 4,718,420 to Lemp. While more accurate than hand-held devices, mechanically aided presses have generally not provided the desired precise accuracy that is required over a range of cutting diameters and for long-term repeated use at a reasonable cost. These mechanisms must not only operate precisely through numerous repetitions of movement, they must also be able to do so after repeated autoclaving since each individual cutting procedure must be performed under sterile conditions. Mechanisms that have been devised to maintain accuracy through repeated use and after repeated autoclaving have been complicated and expensive to manufacture.
Accordingly, there is a need for an improved corneal press that precisely cuts corneal tissue over a range of diameters, and does so reliably for many repeated cuts and numerous corresponding autoclaving treatments over a long period of time. Additionally, there is a need for such a device which is not complicated as to its structure and is relatively inexpensive to manufacture.